Bridget is not trying for a solo riding title, simply the youngest person to circumnavigate the world by motorcycle. I believe the record may currently be held by Kane Avellano or Henry Crew at age 23. Both rode with others for stretches and had their bikes worked on by others, so even if they didn't have a van following them they were assisted by strangers, friends, sponsors, fans, and mechanics. Henry shared that he had to pay many bribes along his route and had quite a few intimidating encounters with people who were not easy to tell if they were either military or legal authority figures vs armed criminal groups (sometimes they are the same).
Being protective of women isn't a universal truth. There are areas where women are not permitted to travel without a male chaperone. Even in the USA the risk of human trafficking or sexual assault are much higher for solo women travelers, especially young ones. It's a reason why they often take measures to try to protect themselves such as GPS tracking, check-ins, not truthfully answering strangers' questions of where they're headed or if they're traveling alone or armed, posting to social media with a 24+ hr delay so they're less likely to be stalked in person from that info, and it's why almost any woman who camps solo has a story to tell about a time (or many) when they packed up their camp and left because someone came over to their campsite uninvited and made them feel uncomfortable and at risk.